CN110494082A

CN110494082A - Ultrasonic elastograph imaging method and system

Info

Publication number: CN110494082A
Application number: CN201880016644.6A
Authority: CN
Inventors: 江鹏; 李双双
Original assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Current assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Priority date: 2018-04-11
Filing date: 2018-04-11
Publication date: 2019-11-22
Anticipated expiration: 2038-04-11
Also published as: CN110494082B; WO2019196033A1; US20210022711A1

Abstract

The present invention relates to a kind of ultrasonic elastograph imaging method and systems, comprising the following steps: obtains the ultrasound image of tested body tissue；Shearing wave is generated in tested body tissue；Motivate the array element transmitting ultrasonic waveform of ultrasonic transducer at the ultrasonic beam for covering the first area in tested body tissue；The ultrasonic echo from first area is received, the second ultrasound echo signal is obtained；Transmission path of the shearing wave in the first area is obtained according to the second ultrasound echo signal.

Description

Ultrasound elastography method and system

Technical Field

The present invention relates to ultrasound imaging, and more particularly, to an ultrasound elastography method and system.

Background

Transient elastography is a method for measuring tissue hardness, and is mainly used in clinical diagnosis of liver, wherein many chronic liver diseases are accompanied by liver fibrosis, during which liver elasticity gradually changes, and liver cirrhosis is finally caused. Transient elastography enables non-invasive monitoring of changes in this process, providing a basis for clinical diagnosis.

The specific method of instantaneous elasticity is to use mechanical vibration pulse excitation to generate instantaneous shear waves in tissues, use a rapid ultrasonic imaging system to acquire radio frequency data and estimate tissue displacement, thereby obtaining the propagation condition of the shear waves in the tissues and further calculating the tissue hardness.

The traditional instantaneous elasticity imaging systems are all one-dimensional systems, and can only obtain the average elasticity result of a small area of a tested body tissue along one direction at the central part of a probe during measurement, so that the examination range is small, and images of the inside of the tested body tissue cannot be provided for doctors, so that the doctors cannot see the internal form of the tested body tissue during instantaneous elasticity measurement, and can only adjust the position of the probe by experience to align the probe to the tissue expected to be measured, and the operation is inconvenient.

Disclosure of Invention

In one embodiment of the present invention, an ultrasound elastography method is provided. The method comprises the following steps: exciting an ultrasonic probe to transmit ultrasonic waves to a tested organism tissue and receive ultrasonic echoes to obtain a first ultrasonic echo signal, wherein the ultrasonic probe comprises an ultrasonic transducer provided with a plurality of array elements; obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal; displaying the ultrasonic image; generating shear waves in the body tissue under test; exciting at least part of array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves at least partially propagate in the first area; receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal; and obtaining a transmission path of the shear wave in the first region according to the second ultrasonic echo signal.

In one embodiment of the present invention, an ultrasound elastography system is provided. The system comprises: the ultrasonic probe comprises a vibrator and an ultrasonic transducer provided with a plurality of array elements, wherein the vibrator can drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissues; the control and data processor controls the ultrasonic transducer and the vibrator and processes data obtained by the ultrasonic transducer; the display device displays the data output by the control and data processor; wherein the control and data processor: exciting the ultrasonic transducer to emit ultrasonic waves to the tested organism tissue and receive ultrasonic echoes to obtain a first ultrasonic echo signal; obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal; controlling the vibrator to drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissues; exciting at least part of array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves propagate at least partially in the first area; receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal; obtaining a transmission path of the shear wave in the first region according to the second ultrasonic echo signal; the display device displays the ultrasound image.

In one embodiment of the present invention, an ultrasound elastography method is provided. The method comprises the following steps: generating shear waves in the body tissue under test; exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves propagate at least partially in the first area; receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal; adjusting the excitation time of the excited array element of the ultrasonic transducer to change the direction of an ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element covers a second area in the tested body tissue, wherein the shear wave at least partially propagates in the second area; receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal; and obtaining a transmission path of the shear wave in a two-dimensional region including the first region and the second region according to at least the second ultrasonic echo signal and the third ultrasonic echo signal.

In one embodiment of the present invention, an ultrasound elastography method is provided. The method comprises the following steps: generating shear waves in the body tissue under test; exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves propagate at least partially in the first area; receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal; generating the shear wave again in the tested body tissue; exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a second region in the tested body tissue, wherein the shear waves propagate at least partially in the second region; receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal; and obtaining a transmission path of the shear wave in a two-dimensional region including the first region and the second region according to at least the second ultrasonic echo signal and the third ultrasonic echo signal.

In one embodiment of the present invention, an ultrasound elastography method is provided. The method comprises the following steps: exciting an ultrasonic probe to transmit ultrasonic waves to a tested organism tissue and receive ultrasonic echoes to obtain a first ultrasonic echo signal, wherein the ultrasonic probe comprises an ultrasonic transducer provided with a plurality of array elements; obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal; displaying the ultrasonic image; determining a region of interest on the ultrasound image; generating shear waves within the body tissue under test based on the determined region of interest such that the generated shear waves propagate at least partially within the region of interest; exciting at least part of the array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form ultrasonic beams covering the region of interest; receiving an ultrasonic echo from the region of interest to obtain an ultrasonic echo signal; and obtaining the transmission path of the shear wave in the region of interest according to the ultrasonic echo signal.

In one embodiment of the present invention, an ultrasound elastography system is provided. The system comprises: the ultrasonic probe comprises a vibrator and an ultrasonic transducer provided with a plurality of array elements, wherein the vibrator can drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissues; the control and data processor controls the ultrasonic transducer and the vibrator and processes data obtained by the ultrasonic transducer; the display device displays the data output by the control and data processor; wherein the control and data processor: exciting an ultrasonic probe to transmit ultrasonic waves to the tissues of a tested body and receive ultrasonic echoes to obtain a first ultrasonic echo signal; obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal; displaying the ultrasonic image; determining a region of interest on the ultrasound image; controlling the vibrator to drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissue based on the determined region of interest, so that the generated shear waves at least partially propagate in the region of interest; exciting at least part of the array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form ultrasonic beams covering the region of interest; receiving an ultrasonic echo from the region of interest to obtain an ultrasonic echo signal; and obtaining the transmission path of the shear wave in the region of interest according to the ultrasonic echo signal.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings of the embodiments can be obtained according to the drawings without creative efforts.

FIG. 1 is a block diagram of an embodiment of a transient elastography system;

FIG. 2 is a schematic structural diagram of an ultrasound probe according to an embodiment;

FIG. 3 is a schematic flow diagram of a method of ultrasound elastography according to an embodiment;

FIG. 4 is a schematic diagram of an ultrasound probe generating shear waves;

FIG. 5 is a schematic diagram of a scanning process according to an embodiment;

FIG. 6 is a schematic flow diagram of a method of ultrasound elastography according to an embodiment;

FIG. 7 is a schematic diagram of a scanning process according to an embodiment;

FIG. 8 is a schematic flow chart diagram of a method of ultrasound elastography according to an embodiment.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, in one embodiment, an ultrasound elastography system may comprise an ultrasound probe 100, a control and data processor 200 and a display 300.

The control and data processor 200 can control the ultrasonic probe 100 to transmit ultrasonic waves to the body tissue to be tested and receive ultrasonic echoes with tissue information reflected from the body tissue to be tested, and convert the ultrasonic echoes into electric signals again to obtain ultrasonic echo signals. The control and data processor 200 receives and processes these ultrasonic echo signals to obtain an ultrasonic image of the body tissue under test. The processing of the ultrasound echo signals by the control and data processor 200 may vary depending on the desired imaging mode and will not be described in detail herein. The obtained ultrasound image may be displayed on the display 300.

Referring to fig. 2, in one embodiment, an ultrasound probe 100 may include a vibrator 110 and an ultrasound transducer 150. The ultrasound transducer 150 may comprise a plurality of array elements, which may be arranged in a one-dimensional or two-dimensional array. The control and data processor 200 can control the vibrator 110 to vibrate, thereby driving the ultrasonic transducer 150 to vibrate. In operation, the ultrasound probe 100 is applied to the surface of the body tissue being examined. At this time, the vibrator 110 drives the ultrasonic transducer 150 to vibrate, and a shear wave propagating from a contact position of the body tissue and the ultrasonic transducer 150 to the inside of the body tissue to be tested can be generated in the body tissue to be tested. Control and data processor 200 may then control ultrasonic transducer 150 to emit ultrasonic waves into the body tissue under test to track the shear waves, as described in more detail below.

In one embodiment, the ultrasound probe 100 may further include a pressure sensor 130. The pressure sensor 130 can sense the pressure between the ultrasonic probe 100 (or the ultrasonic transducer 150) and the tested body tissue, and feed the pressure back to the control and data processor 200.

In one embodiment, the aforementioned shear wave may be generated not by driving the ultrasonic transducer 150 by the vibrator 110, but by a separate vibrator (not shown) provided separately from the ultrasonic probe 100, and then the multi-element ultrasonic transducer 150 of the ultrasonic probe 100 emits an ultrasonic wave to track the shear wave. In such an embodiment, the aforementioned vibrator 110 may not be included in the ultrasound probe 100.

Referring to fig. 3, in one embodiment, an ultrasound elastography method, such as a transient elastography method, implemented using the aforementioned ultrasound elastography system may include the following steps.

And S001, obtaining an ultrasonic image of the tested body tissue.

In this embodiment, when obtaining the elastic parameters or the elastic image of the tested body tissue (described in detail below), a conventional ultrasound image of the tested body tissue, such as a B-mode image, a C-mode image, a D-mode image or other similar ultrasound images, may also be obtained. The obtained conventional ultrasonic image can be displayed on the display 300, which is convenient for the doctor to observe the condition of the tested body tissue when scanning and obtaining the elasticity parameter or the elasticity image of the tested body tissue, so as to be more beneficial to obtaining the elasticity of the tested body tissue.

In this step, the control and data processor 200 may excite the ultrasonic transducer 150 of the ultrasonic probe 100 to emit ultrasonic waves to the tested body tissue and receive ultrasonic echoes, so as to obtain ultrasonic echo signals. Herein, the ultrasound echo signal used for obtaining such a conventional ultrasound image as described above is referred to as a first ultrasound echo signal. The control and data processor 200 receives the first ultrasonic echo signal and processes it accordingly, so as to obtain an ultrasonic image of the tested body tissue, such as a B-mode image, a C-mode image, a D-mode image or other similar ultrasonic images, according to the first ultrasonic echo signal. The obtained ultrasound image may be displayed on the display 300.

In step S002, shear waves are generated in the body tissue to be tested.

In this step, shear waves may be generated within the body tissue being examined. For example, as described above, the control and data processor 200 controls the vibrator 110 of the ultrasonic probe 100 to vibrate so as to drive the ultrasonic transducer 150 attached to the surface of the body tissue under test to vibrate, thereby generating shear waves propagating inward from the position where the body tissue under test is attached to the ultrasonic transducer 150, as shown in fig. 4, in a two-dimensional plane, the shear waves thus generated are approximately like waves formed by the water surface thrown into the stone, and the contact point of the ultrasonic probe 100 with the body tissue under test spreads inward into the body tissue under test. In this process, the ultrasound transducer 150 is typically placed under pressure against the surface of the body tissue being examined. This pressure may be sensed by the pressure sensor 130 in the ultrasound probe 100 and fed back to the control and data processor 200. The control and data processor 200 may output the current pressure sensed by the pressure sensor 130 to the user in various ways. For example, the sensed current pressure may be output to the user by a digital, graphical, acoustic or optical signal, or the like.

In other embodiments, the shear waves may also be generated by a separate vibrator that is located separately from the ultrasound probe 100.

In step S003, the shear wave is tracked by using ultrasonic waves, and a transmission path of the shear wave is obtained.

After generating the shear wave in step S002, the control and data processor 200 may send an excitation pulse to the ultrasonic transducer 150 to excite at least a part of the array elements in the ultrasonic transducer 150 to emit ultrasonic waves into the body tissue under test. Each time the ultrasound wave is transmitted, all the elements in the ultrasound transducer 150 may participate in the transmission, or some of the elements may participate in the transmission. By controlling the time at which the array elements participating in the transmission (and the array elements to be excited in the current transmission) are excited by the excitation pulse, the direction and/or width, etc. of the ultrasonic beam finally formed by the ultrasonic waves transmitted by the array elements can be adjusted, so that the ultrasonic waves transmitted by the array elements participating in the transmission form an ultrasonic beam which propagates along a desired angle or in a desired region (or covers the desired region). In this embodiment, the control and data processor 200 may control the time for which the array element to be excited (and the array element participating in the current transmission) is excited by the excitation pulse, so that the ultrasonic wave transmitted by the array element forms an ultrasonic beam covering a first region of the body tissue under test, in which the generated shear wave propagates at least partially, and the ultrasonic beam may track the propagation process of the shear wave in the first region.

In this embodiment, the ultrasonic beam formed by the ultrasonic waves emitted by at least part of the array elements may be a focused ultrasonic beam, or may be a non-focused ultrasonic beam, such as a planar ultrasonic beam or a divergent ultrasonic beam.

The ultrasonic transducer 150 may receive an ultrasonic echo from the first region to obtain an ultrasonic echo signal. Herein, an ultrasound echo signal obtained from an ultrasound echo from the first region is referred to as a second ultrasound echo signal.

This process of transmitting an ultrasonic beam covering the first region and receiving its ultrasonic echo to obtain a second ultrasonic echo signal may be repeated a plurality of times, as shown in fig. 5.

The control and data processor 200 may receive and process the second ultrasonic echo signals to obtain a transmission path of the shear wave in the first region. For example, the control and data processor 200 may perform correlation calculation on the second ultrasonic echo signals obtained multiple times, so as to obtain a transmission path of the shear wave in the first region.

And step S004, calculating the elastic parameters of the tested organism tissues according to the obtained shear wave transmission path.

After obtaining the propagation path of the shear wave in the first region, the control and data processor 200 may calculate an elasticity parameter representing the elasticity of the tested body tissue in the first region according to the propagation path of the shear wave in the first region. The elastic parameter may be the speed of transmission of the shear wave in the first region, the young's modulus of the subject's body tissue in the first region, the shear modulus of the subject's body tissue in the first region, the degree of attenuation of the shear wave in the subject's body tissue in the first region, or the elastic parameter ratio of the subject's body tissue at different locations in the first region, etc.

For example, in one embodiment, the displacement of the shear wave over time may be calculated from the resulting propagation path of the shear wave in the first region, and the bit removal may be used to obtain the propagation velocity of the shear wave in the first region over time. The transfer velocity calculated here may be the shear wave transfer velocity at each depth within the first region, or it may be the average of the shear wave transfer velocities over any segment of depth.

In addition, in one embodiment, other elastic parameters of the body tissue under test in the first region may be calculated based on the velocity of the shear wave transmitted in the first region.

For example, the young's modulus of the tissue can be calculated based on the shear wave propagation velocity using the following formula:

E＝3ρV²

e is Young modulus, which represents the tissue hardness of the tested organism tissue; rho is the tissue density of the tested organism tissue; v is the shear wave propagation velocity in the body tissue under test.

Other parameters characterizing the elasticity of the tested body tissue in the first region, such as shear modulus, degree of shear wave attenuation, etc., can also be calculated using corresponding methods, which are not further described herein.

Step S006, displaying the elastic parameters and/or the ultrasonic image of the tested body tissue.

After the foregoing elasticity parameters are obtained, the obtained elasticity parameters may be displayed on the display 300. These elasticity parameters may be displayed in numerical values, colors, graphs, and the like. In one embodiment, the propagation trajectory of the shear wave in the first region obtained in the previous step may also be displayed on the display 300. In one embodiment, the transmission trajectory of the elastic parameters or the shear waves may be displayed on the display 300 simultaneously with the conventional ultrasound image of the tested body tissue obtained in step S001.

In the embodiments, the conventional imaging process for obtaining the conventional ultrasound image and the instantaneous elastography process for obtaining the elasticity parameter are completed by the same probe, that is, only the same probe is needed, not only the conventional ultrasound image but also the elasticity parameter of the tissue can be obtained, so that a doctor can see the image inside the tested body when performing elasticity measurement, and the doctor can find the tissue needing the elasticity measurement conveniently.

Referring to fig. 6 and 7, in one embodiment of the present invention, an ultrasound elastography method implemented using the aforementioned ultrasound elastography system may include the following steps.

And step S010, obtaining an ultrasonic image of the tested body tissue. This step may be the same as or similar to step S001 of the previous embodiment and will not be described in detail here.

Step S011, shear waves are generated in the body tissue under test. This step may be the same as or similar to step S002 of the previous embodiment and will not be described in detail herein.

Step S012 is to track the shear wave in the first region using the ultrasonic wave, and obtain a second ultrasonic echo signal.

In this step, similar to step S003 of the previous embodiment, after the shear wave is generated in step S011, the control and data processor 200 may send an excitation pulse to the ultrasonic transducer 150 to excite at least a part of the array elements of the ultrasonic transducer 150 to emit ultrasonic waves into the body tissue to be tested. Each time the ultrasound wave is transmitted, all the elements in the ultrasound transducer 150 may participate in the transmission, or some of the elements may participate in the transmission. By controlling the time at which the array elements participating in the transmission (and the array elements to be excited in the current transmission) are excited by the excitation pulse, the direction and/or width, etc. of the ultrasonic beam finally formed by the ultrasonic waves transmitted by the array elements can be adjusted, so that the ultrasonic waves transmitted by the array elements participating in the transmission finally form an ultrasonic beam which propagates along a desired angle or in a desired area (or covers the desired area). In this embodiment, the control and data processor 200 may control the time for which the array element to be excited (and the array element participating in the current transmission) is excited by the excitation pulse, so that the ultrasonic wave transmitted by the array element forms an ultrasonic beam covering a first region of the body tissue under test, in which the generated shear wave propagates at least partially, and the ultrasonic beam may track the propagation process of the shear wave in the first region.

The ultrasonic transducer 150 may receive an ultrasonic echo from the first region to obtain an ultrasonic echo signal. Here, the ultrasonic echo signal obtained by the ultrasonic echo from the first region in the present embodiment is still referred to as a second ultrasonic echo signal.

The process of transmitting an ultrasonic beam covering the first region and receiving an ultrasonic echo thereof to obtain a second ultrasonic echo signal may also be repeated a plurality of times.

Similarly, in step S013, the control and data processor 200 may control or adjust the time at which the array element to be excited (and the array element participating in the current transmission) is excited by the excitation pulse, and change the direction of the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic wave emitted by the excited array element forms an ultrasonic beam covering a second region in the body tissue of the subject in which the generated shear wave at least partially propagates, so that the ultrasonic beam can track the propagation process of the shear wave in the second region.

The ultrasonic transducer 150 may receive the ultrasonic echo from the second region to obtain an ultrasonic echo signal. Here, an ultrasonic echo signal obtained from an ultrasonic echo from the second region is referred to as a third ultrasonic echo signal herein.

The process of transmitting an ultrasonic beam covering the second region and receiving an ultrasonic echo thereof to obtain a third ultrasonic echo signal may also be repeated a plurality of times.

In this embodiment, it is also possible to similarly transmit an ultrasonic beam covering a third region or more and receive the ultrasonic echoes of the respective regions to obtain corresponding ultrasonic echo signals, as shown in fig. 7.

Step S014, a shear wave transmission path in the two-dimensional region is obtained from the ultrasonic echo signal.

The first and second regions may be adjacent or partially coincident, forming a two-dimensional region. In the case where ultrasonic beams covering more regions are emitted, two of these regions are adjacent to each other or partially coincide, and all of these regions form a two-dimensional region. In step S014, the control and data processor 200 may obtain a transmission path of the shear wave in the two-dimensional region (i.e., the two-dimensional region including the first region and the second region or the two-dimensional region including more regions) according to the second ultrasonic echo signal and the third ultrasonic echo signal or the ultrasonic echo signals of more regions. For example, in one embodiment, the control and data processor 200 may perform correlation calculations on ultrasound echo signals obtained at different times covering the same region, thereby obtaining a propagation path of the shear wave in the region. Similar correlation calculations are performed for all the regions forming the two-dimensional region, and the propagation paths of the shear wave in all the regions forming the two-dimensional region are obtained, thereby obtaining the propagation paths of the shear wave in the two-dimensional region.

Step S015, an elastic parameter in the two-dimensional region is calculated from the shear wave propagation path.

In this step, similarly to step S004 in the foregoing embodiment, the elastic parameter in the two-dimensional region can be calculated from the shear wave propagation path in a similar manner. The elastic parameter may be a transmission speed of the shear wave in the two-dimensional region, a young's modulus of the tested body tissue in the two-dimensional region, a shear modulus of the tested body tissue in the two-dimensional region, an attenuation degree of the shear wave in the tested body tissue in the two-dimensional region, or an elastic parameter ratio of the tested body tissue at different positions in the two-dimensional region, or the like.

In one embodiment, these elastic parameters may be calculated over a two-dimensional region directly based on the shear wave propagation path over the two-dimensional region.

In another embodiment, the elastic parameters in each region may be calculated based on the shear wave propagation paths in each region, and then combined into elastic parameters in a two-dimensional region. For example, in one embodiment, the elastic parameter in the first region may be obtained from the shear wave propagation path in the first region, such as the propagation speed of the shear wave in the first region, the young's modulus of the body tissue under test in the first region, the shear modulus of the body tissue under test in the first region, the degree of attenuation of the shear wave in the body tissue under test in the first region, or the elastic parameter ratio of the body tissue under test at different positions in the first region, etc.; and obtaining an elastic parameter in the second region based on the shear wave propagation path in the second region, such as a propagation speed of the shear wave in the second region, a young's modulus of the body tissue under test in the second region, a shear modulus of the body tissue under test in the second region, a degree of attenuation of the shear wave in the body tissue under test in the second region, or an elastic parameter ratio of the body tissue under test at different positions in the second region, and so on. From the elasticity parameter in the first region and the elasticity parameter in the second region, the elasticity parameter of the two-dimensional region formed by the second region and the second region can be obtained.

Step S016, displaying the elasticity parameters and/or the ultrasound image.

The elasticity parameter in the two-dimensional region obtained in step S015 may be displayed on the display 300. The elasticity parameters of such a two-dimensional region may be displayed as a two-dimensional image frame. The form may be various, for example, it may be displayed as a numerical image frame, a pseudo color image frame using color coding, a gray image frame, and the like. In general, when elastic parameters in the aforementioned plurality of regions (e.g., the first region and the second region) constituting the two-dimensional region are calculated once, these elastic parameters can be combined into one frame of two-dimensional elastic image. As scanning continues to obtain the elasticity parameters in these regions, more frames of two-dimensional elasticity images may continue to be obtained.

In the embodiments, not only the conventional imaging process for obtaining the conventional ultrasonic image and the instantaneous elastography process for obtaining the elastic parameters are completed through the same probe, but also the two-dimensional elastic image in the two-dimensional area can be obtained, and the two-dimensional distribution condition of the elastic parameters in the two-dimensional area is provided for a doctor, so that the doctor can diagnose the tested body tissue more conveniently.

In one embodiment, a plurality of shear waves can be generated, and after one shear wave is generated, ultrasonic echo signals of a part of the plurality of regions or the propagation paths of the shear waves in the corresponding region or the elasticity parameters in the corresponding region are obtained by the method similar to the above method; after the shear wave is generated again, the ultrasonic echo signal of another part of the multiple regions or the propagation path of the shear wave in the corresponding region or the elasticity parameter in the corresponding region are obtained. Through generating the shear wave for a plurality of times, the ultrasonic echo signals of all the plurality of regions or the propagation path of the shear wave in the corresponding region or the elasticity parameter in the corresponding region are obtained.

For example, in one embodiment, an ultrasound elastography method may comprise:

generating shear waves in the body tissue to be tested;

exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear wave at least partially propagates in the first area;

receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal;

generating the shear wave in the tested organism tissue again;

exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form ultrasonic beams covering a second area in the tested body tissue, wherein the shear waves at least partially propagate in the second area;

receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal;

and obtaining a transmission path of the shear wave in a two-dimensional region containing the first region and the second region according to at least the second ultrasonic echo signal and the third ultrasonic echo signal.

In this embodiment, the two or more generated shear waves may be the same shear waves generated at the same location and with the same parameters.

In one embodiment, in ultrasound elastography, a conventional ultrasound image of the tested body tissue may be obtained, and then a region of interest is determined based on the ultrasound image, and the elasticity of the body tissue in the region of interest is measured, as shown in fig. 8. The user or the ultrasound elastography system can determine the region whose elasticity is desired to be measured by means of conventional ultrasound images, and the ultrasound elastography system can more accurately generate and track shear waves through the region of interest to obtain elasticity parameters of the region of interest. Therefore, the target needing elastic measurement can be accurately positioned, a doctor can conveniently and accurately obtain the elastic parameters of the region of interest of the doctor, and the usability is improved.

Referring to fig. 8, in this embodiment, in step S020, the control and data processor 200 may excite the ultrasonic probe 100 to transmit an ultrasonic wave to the measured body tissue and receive an ultrasonic echo, obtain a first ultrasonic echo signal, obtain an ultrasonic image of the measured body tissue according to the first ultrasonic echo signal, and display the ultrasonic image on the display 300. The ultrasound image may be a B-mode image, a C-mode image, a D-mode image, or other mode image. This step S020 may be similar to step S001 in the previous embodiment, and will not be described in detail here.

In step S021, the control and data processor 200 may determine a region of interest on the ultrasound image. The control and data processor 200 may determine the region of interest based on a signal input by a user through a human interaction device (not shown in fig. 1) to select or define the region of interest. For example, the user may select or draw a region of interest on the ultrasound image displayed on the display 300 via the human-computer interaction device, such as drawing a box or the like defining the region of interest, and the control and data processor 200 receives such input from the user, and determines the region of interest on the ultrasound image based on the input.

In one embodiment, the control and data processor 200 may also automatically determine the region of interest. For example, the control and data processor 200 may process the ultrasound image according to a predetermined rule to identify a region of interest.

After the region of interest is determined, at step S022, shear waves propagating within the region of interest can be generated. For example, the control and data processor 200 may control the vibrator 110 provided in the ultrasonic probe 100 to drive the ultrasonic transducer 150 to vibrate so as to generate shear waves propagating in the region of interest, or control a separate vibrator provided separately from the ultrasonic probe 100 to vibrate so as to generate shear waves propagating in the region of interest. In this process, based on the position of the region of interest determined on the ultrasound image, the position of the ultrasound transducer 150 of the ultrasound probe 100 in contact with the surface of the body tissue to be measured or the position of the separate vibrator provided separately from the ultrasound probe 100 in contact with the body tissue to be measured may be adjusted, so that the generated shear wave can be or better propagated in the region of interest, thereby improving the accuracy and reliability of the elasticity measurement.

At step S023, the control and data processor 200 may excite at least a portion of the array elements of the ultrasound transducer 150 to emit ultrasound waves and control the excitation time of each excited array element so that the ultrasound waves emitted by the excited array elements form an ultrasound beam covering the region of interest, and receive the ultrasound echoes from the region of interest through the ultrasound probe to obtain ultrasound echo signals. The ultrasound beam formed by the ultrasound emitted by the excited array elements can be a focused ultrasound beam or an unfocused ultrasound beam.

In step S024, the control and data processor 200 may obtain a propagation path of the shear wave in the region of interest from the ultrasonic echo signal obtained in step S023. The method of obtaining the transmission path in this step may be similar to that in step S003 or S014 in the foregoing embodiment, and will not be described in detail here.

In one embodiment, the shear waves in the region of interest may be tracked in regions, and then the shear wave propagation path in the entire region of interest may be obtained from the ultrasound echo signals obtained from these regions, or the shear wave propagation path in the entire region of interest may be obtained from the shear wave propagation paths in these regions obtained separately.

For example, in one embodiment, in steps S023 and S024, the control and data processor 200 may excite at least a part of the array elements of the ultrasound transducer to emit ultrasound waves and control the excitation time of each excited array element so that the ultrasound waves emitted by the excited array element form an ultrasound beam covering a first region in the region of interest, and receive the ultrasound echoes from the first region through the ultrasound probe to obtain a second ultrasound echo signal. Subsequently, the control and data processor 200 may adjust the excitation time of the excited array element to change the direction of the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element covers a second region in the region of interest, and receive the ultrasonic echo from the second region to obtain a third ultrasonic echo signal. Similarly, the control and data processor 200 may also control or adjust the excitation time of the excited elements, changing the direction of the ultrasound beam formed by the ultrasound waves emitted by them to scan more areas with the ultrasound beam to track the shear waves therein. All these regions form the region of interest. Accordingly, the control and data processor 200 may obtain a propagation path of the shear wave in the region of interest at least according to the second ultrasonic echo signal and the third ultrasonic echo signal.

In step S025, the control and data processor 200 may calculate an elasticity parameter representing elasticity of body tissue in the region of interest according to a propagation path of the shear wave in the region of interest. The elasticity parameters may include the speed of shear wave propagation within the region of interest, the young's modulus of the subject's body tissue within the region of interest, the shear modulus of the subject's body tissue within the region of interest, the degree of attenuation of the shear wave in the subject's body tissue within the region of interest, the ratio of the elasticity parameters of the subject's body tissue at different locations within the region of interest, or other elasticity parameters characterizing the elasticity of the tissue.

In this step, a method similar to that in step S004 or S015 in the foregoing embodiment may be used as a method for calculating these elasticity parameters, and details thereof are not described here.

In one embodiment, the control and data processor 200 may also obtain an elasticity image, such as a two-dimensional elasticity image or a three-dimensional elasticity image, of the entire region of interest based on the elasticity parameters obtained by the calculation. In this embodiment, the form of the elastic image may be various forms, such as a numerical image, a pseudo color image using color coding, a grayscale image, and the like.

In step S026, the control and data processor 200 may display the acquired elasticity parameter on the display 300. In this embodiment, the elasticity parameter may be displayed as a numerical value, a graph, or the like, or may be displayed as an elasticity image as described above.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product.

The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can store or a data storage device, such as a server, a data center, etc., that is integrated with one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the embodiments provided in the present invention, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implementing, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

A method of ultrasound elastography, comprising:

exciting an ultrasonic probe to transmit ultrasonic waves to a tested organism tissue and receive ultrasonic echoes to obtain a first ultrasonic echo signal, wherein the ultrasonic probe comprises an ultrasonic transducer provided with a plurality of array elements;

obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal;

displaying the ultrasonic image;

generating shear waves in the body tissue under test;

exciting at least part of array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves propagate at least partially in the first area;

receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal;

and obtaining a transmission path of the shear wave in the first region according to the second ultrasonic echo signal.
The method of claim 1, wherein: the ultrasound beam formed is either a focused ultrasound beam or an unfocused ultrasound beam.
The method of claim 1, further comprising: and calculating an elasticity parameter representing the elasticity of the tested body tissue in the first region according to the transmission path of the shear wave in the first region.
The method of claim 3, further comprising: and displaying the elasticity parameter.
A method according to claim 3 or claim 4, wherein said elastic parameters include the speed of propagation of said shear wave in said first region, the Young's modulus of the subject's body tissue in said first region, the shear modulus of the subject's body tissue in said first region, the degree of attenuation of said shear wave in the subject's body tissue in said first region, or the ratio of elastic parameters of the subject's body tissue at different locations in said first region.
The method of claim 1, further comprising:

adjusting the excitation time of the excited array element of the ultrasonic transducer to change the direction of an ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element covers a second area in the tested body tissue, wherein the shear wave at least partially propagates in the second area;

receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal;

and obtaining a transmission path of the shear wave in the second region according to the third ultrasonic echo signal.
The method of claim 6, further comprising:

obtaining a propagation path of the shear wave within a two-dimensional region including the first region and the second region from at least a propagation path of the shear wave within the first region and a propagation path of the shear wave within the second region;

and calculating an elastic parameter representing the elasticity of the tested body tissue in the two-dimensional area according to the transmission path of the shear wave in the two-dimensional area.
The method of claim 7, further comprising: and displaying an elasticity parameter representing the elasticity of the tested body tissue in the two-dimensional area.
The method of claim 7, further comprising: and displaying the elasticity parameter representing the elasticity of the tested body tissue in the two-dimensional area as a two-dimensional image.
A method according to any one of claims 7 to 9, wherein said elastic parameters comprise the speed of propagation of said shear wave in said two-dimensional region, the young's modulus of the body tissue under test in said two-dimensional region, the shear modulus of the body tissue under test in said two-dimensional region, the degree of attenuation of said shear wave in the body tissue under test in said two-dimensional region, or the ratio of the elastic parameters of the body tissue under test at different locations in said two-dimensional region.
An ultrasound elastography system, comprising:

the ultrasonic probe comprises a vibrator and an ultrasonic transducer provided with a plurality of array elements, wherein the vibrator can drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissues;

the control and data processor controls the ultrasonic transducer and the vibrator and processes data obtained by the ultrasonic transducer;

the display device displays the data output by the control and data processor;

wherein the control and data processor:

exciting the ultrasonic transducer to emit ultrasonic waves to the tested organism tissue and receive ultrasonic echoes to obtain a first ultrasonic echo signal;

obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal;

controlling the vibrator to drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissues;

exciting at least part of array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves propagate at least partially in the first area;

receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal;

obtaining a transmission path of the shear wave in the first region according to the second ultrasonic echo signal;

the display device displays the ultrasound image.
The system of claim 11, wherein: the ultrasound beam formed is either a focused ultrasound beam or an unfocused ultrasound beam.
The system of claim 11, wherein: the control and data processor also calculates an elasticity parameter representing the elasticity of the tested body tissue in the first region according to the transmission path of the shear wave in the first region.
The system of claim 13, wherein: the display device also displays the elasticity parameter.
A system according to claim 13 or 14, wherein said elastic parameters include the speed of propagation of said shear wave in said first region, the young's modulus of the body tissue under test in said first region, the shear modulus of the body tissue under test in said first region, the degree of attenuation of said shear wave in the body tissue under test in said first region, or the ratio of the elastic parameters of the body tissue under test at different locations in said first region.
The system of claim 11, wherein the control and data processor further:

adjusting the excitation time of the excited array element of the ultrasonic transducer to change the direction of an ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element covers a second area in the tested body tissue, wherein the shear wave at least partially propagates in the second area;

receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal;

and obtaining a transmission path of the shear wave in the second region according to the third ultrasonic echo signal.
The system of claim 16, wherein the control and data processor further:

obtaining a propagation path of the shear wave within a two-dimensional region including the first region and the second region from at least a propagation path of the shear wave within the first region and a propagation path of the shear wave within the second region;

and calculating an elastic parameter representing the elasticity of the tested body tissue in the two-dimensional area according to the transmission path of the shear wave in the two-dimensional area.
The system of claim 17, wherein: the display device also displays an elasticity parameter characterizing the elasticity of the body tissue under test within the two-dimensional region.
The system of claim 17, wherein: and the display device displays the elasticity parameter representing the elasticity of the tested body tissue in the two-dimensional area as a two-dimensional image.
A system according to any one of claims 17 to 19, wherein said elastic parameters include the speed of propagation of said shear wave in said two-dimensional region, the young's modulus of the body tissue under test in said two-dimensional region, the shear modulus of the body tissue under test in said two-dimensional region, the degree of attenuation of said shear wave in the body tissue under test in said two-dimensional region, or the ratio of the elastic parameters of the body tissue under test at different locations in said two-dimensional region.
A method of ultrasound elastography, comprising:

generating shear waves in the body tissue under test;

exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves propagate at least partially in the first area;

receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal;

adjusting the excitation time of the excited array element of the ultrasonic transducer to change the direction of an ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element covers a second area in the tested body tissue, wherein the shear wave at least partially propagates in the second area;

receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal;

and obtaining a transmission path of the shear wave in a two-dimensional region including the first region and the second region according to at least the second ultrasonic echo signal and the third ultrasonic echo signal.
The method of claim 21, further comprising:

and calculating an elastic parameter representing the elasticity of the tested body tissue in the two-dimensional area according to the transmission path of the shear wave in the two-dimensional area.
The method of claim 22, further comprising: and displaying an elasticity parameter representing the elasticity of the tested body tissue in the two-dimensional area.
The method of claim 22, further comprising: and displaying the elasticity parameter representing the elasticity of the tested body tissue in the two-dimensional area as a two-dimensional image.
A method according to any one of claims 22 to 24, wherein said elastic parameters comprise the speed of propagation of said shear wave in said two-dimensional region, the young's modulus of the body tissue under test in said two-dimensional region, the shear modulus of the body tissue under test in said two-dimensional region, the degree of attenuation of said shear wave in the body tissue under test in said two-dimensional region or the ratio of the elastic parameters of the body tissue under test at different locations in said two-dimensional region.
A method of ultrasound elastography, comprising:

generating shear waves in the body tissue under test;

exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the tested body tissue, wherein the shear waves propagate at least partially in the first area;

receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal;

generating the shear wave again in the tested body tissue;

exciting at least part of array elements of an ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a second region in the tested body tissue, wherein the shear waves propagate at least partially in the second region;

receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal;

and obtaining a transmission path of the shear wave in a two-dimensional region including the first region and the second region according to at least the second ultrasonic echo signal and the third ultrasonic echo signal.
A method of ultrasound elastography, comprising:

exciting an ultrasonic probe to transmit ultrasonic waves to a tested organism tissue and receive ultrasonic echoes to obtain a first ultrasonic echo signal, wherein the ultrasonic probe comprises an ultrasonic transducer provided with a plurality of array elements;

obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal;

displaying the ultrasonic image;

determining a region of interest on the ultrasound image;

generating shear waves within the body tissue under test based on the determined region of interest such that the generated shear waves propagate at least partially within the region of interest;

exciting at least part of the array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form ultrasonic beams covering the region of interest;

receiving an ultrasonic echo from the region of interest to obtain an ultrasonic echo signal;

and obtaining the transmission path of the shear wave in the region of interest according to the ultrasonic echo signal.
The method of claim 27, wherein: the ultrasound beam formed is either a focused ultrasound beam or an unfocused ultrasound beam.
The method of claim 27, further comprising: and calculating an elasticity parameter representing the elasticity of the tested body tissue in the region of interest according to the transmission path of the shear wave in the region of interest.
The method of claim 29, further comprising:

obtaining an elasticity image in the region of interest according to the elasticity parameters;

and displaying the elastic image.
A method according to claim 29 or 30, wherein the elastic parameters include the speed of propagation of the shear wave in the region of interest, the young's modulus of the body tissue under test in the region of interest, the shear modulus of the body tissue under test in the region of interest, the degree of attenuation of the shear wave in the body tissue under test in the region of interest or the elastic parameter ratio of the body tissue under test at different locations in the region of interest.
A method according to claim 27 wherein exciting at least some of the elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each element excited such that the ultrasonic waves emitted by the excited elements form an ultrasonic beam covering the region of interest, receiving ultrasonic echoes from the region of interest to obtain ultrasonic echo signals, and obtaining the propagation path of the shear waves in the region of interest from the ultrasonic echo signals comprises:

exciting at least part of the array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the region of interest;

receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal;

adjusting the excitation time of the excited array element to change the direction of an ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element covers a second area in the region of interest;

receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal;

and obtaining a transmission path of the shear wave in the region of interest at least according to the second ultrasonic echo signal and the third ultrasonic echo signal.
An ultrasound elastography system, comprising:

the ultrasonic probe comprises a vibrator and an ultrasonic transducer provided with a plurality of array elements, wherein the vibrator can drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissues;

the control and data processor controls the ultrasonic transducer and the vibrator and processes data obtained by the ultrasonic transducer;

the display device displays the data output by the control and data processor;

wherein the control and data processor:

exciting an ultrasonic probe to transmit ultrasonic waves to the tissues of a tested body and receive ultrasonic echoes to obtain a first ultrasonic echo signal;

obtaining an ultrasonic image of the tested body tissue according to the first ultrasonic echo signal;

displaying the ultrasonic image;

determining a region of interest on the ultrasound image;

controlling the vibrator to drive the ultrasonic transducer to vibrate so as to generate shear waves in the tested body tissue based on the determined region of interest, so that the generated shear waves at least partially propagate in the region of interest;

exciting at least part of the array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form ultrasonic beams covering the region of interest;

receiving an ultrasonic echo from the region of interest to obtain an ultrasonic echo signal;

and obtaining the transmission path of the shear wave in the region of interest according to the ultrasonic echo signal.
The system of claim 33, wherein: the ultrasound beam formed is either a focused ultrasound beam or an unfocused ultrasound beam.
The system of claim 33, wherein: and the control and data processor also calculates an elasticity parameter representing the elasticity of the tested body tissue in the region of interest according to the transmission path of the shear wave in the region of interest.
The system of claim 35, wherein: the control and data processor further:

obtaining an elasticity image in the region of interest according to the elasticity parameters;

and displaying the elastic image.
A system according to claim 35 or 36, wherein said elastic parameters include the speed of propagation of said shear wave in said region of interest, the young's modulus of the body tissue under test in said region of interest, the shear modulus of the body tissue under test in said region of interest, the degree of attenuation of said shear wave in the body tissue under test in said region of interest or the elastic parameter ratio of the body tissue under test at different locations in said region of interest.
The system of claim 33, wherein: the control and data processor:

exciting at least part of the array elements of the ultrasonic transducer to emit ultrasonic waves and controlling the excitation time of each excited array element so that the ultrasonic waves emitted by the excited array elements form an ultrasonic beam covering a first area in the region of interest;

receiving an ultrasonic echo from the first region to obtain a second ultrasonic echo signal;

adjusting the excitation time of the excited array element to change the direction of an ultrasonic beam formed by the ultrasonic wave emitted by the excited array element, so that the ultrasonic beam formed by the ultrasonic wave emitted by the excited array element covers a second area in the region of interest;

receiving an ultrasonic echo from the second area to obtain a third ultrasonic echo signal;

and obtaining a transmission path of the shear wave in the region of interest at least according to the second ultrasonic echo signal and the third ultrasonic echo signal.